Oooh but there are so many species you could consider.. 
Gonna paste a post I erroneously made in another thread, might be more appropriate here
Unfortunately, quite a few of them are still acidic water fishes 
Gonna paste a post I erroneously made in another thread, might be more appropriate here

- Blue Rams
- Bolivian Rams
- Apistogramma species - agassizii and cacatuoides are quite common but there are hundreds of species available such as panduro, macmasteri, viejita.. all stunners
- Nanochromis species.. transvestitus are gorgeous; females prettier than males (hence the species name)
- Nannacara anomala aka The Golden Dwarf Cichlid
- A pair of juvenile Keyhole cichlids
- Pelvicachromis taeniatus.. less common than their genus-mates pulcher (the Krib) and sometimes just that little bit more special.. very easily bred, too
- Dicrossus species.. my favourite of the lot - filamentosis are the more brightly coloured species, with maculatus being less bright but equally gorgeous, in a more subtle way
- Lamprologus ocellatus also known as the shell-dweller. These guys are from the rift lakes and thrive in a pH up to 9. In a three foot tank you'd be able to set up a stunning community for them. They're not as immediately colourful or bright, but they're beautiful in a very subtle way.